Low molecular weight cations with valency, i.e. charge, <+3 fail to condense DNA in aqueous solutions under normal conditions. However, cationic molecules with the charge <+3 can be polymerized in the presence of DNA and the resulting polymers can cause DNA to condense into compact structures. Such an approach is known in synthetic polymer chemistry as template polymerization. During this process, monomers (which are initially weakly associated with the template) are positioned along template's backbone, thereby promoting their polymerization. Weak electrostatic association of the nascent polymer and the template becomes stronger with chain growth of the polymer. Trubetskoy et al used two types of polymerization reactions to achieve DNA condensation: step polymerization and chain polymerization (V S Trubetskoy, V G Budker, L J Hanson, P M Slattum, J A Wolff, L E Hagstrom. Nucleic Acids Res. 26:4178-4185, 1998) U.S. Ser. No. 08/778,657, U.S. Ser. No. 09/000,692, U.S. Ser. No. 97/24089, U.S. Ser. No. 09/070299, and U.S. Ser. No. 09/464,871. Bis(2-aminoethyl)-1,3-propanediamine (AEPD), a tetramine with 2.5 positive charges per molecule at pH 8 was polymerized in the presence of plasmid DNA using cleavable disulfide amino-reactive cross-linkers dithiobis (succinimidyl propionate) and dimethyl-3,3′-dithiobispropionimidate. Both reactions yielded DNA/polymer complexes with significant retardation in agarose electrophoresis gels demonstrating significant binding and DNA condensation. Treatment of the polymerized complexes with 100 mM dithiothreitol (DTT) resulted in the pDNA returning to its normal supercoiled position following electrophoresis proving thus cleavage the backbone of the. The template dependent polymerization process was also tested using a 14 mer peptide encoding the nuclear localizing signal (NLS) of SV40 T antigen as a cationic “macromonomer”. Other studies included pegylated comonomer (PEG-AEPD) into the reaction mixture and resulted in “worm”-like structures (as judged by transmission electron microscopy) that have previously been observed with DNA complexes formed from block co-polymers of polylysine and PEG (M A Wolfert, E H Schacht, V Toncheva, K Ulbrich, O Nazarova, L W Seymour. Human Gene Ther. 7:2123-2133, 1996). Blessing et al used bisthiol derivative of spermine and reaction of thiol-disulfide exchange to promote chain growth. The presence of DNA accelerated the polymerization reaction as measured the rate of disappearance of free thiols in the reaction mixture (T Blessing, J S Remy, J P Behr. J. Am. Chem. Soc. 120:8519-8520, 1998).